Question: $ { \left[\begin{array}{r}{-1} \\ {3} \\ {1}\end{array}\right]+\left[\begin{array}{r}{-2} \\ {4} \\ {4}\end{array}\right] = {?} } $
Answer: To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{r}{-1}+{-2} \\ {3}+{4} \\ {1}+{4}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{r}{-3} \\ {7} \\ {5}\end{array}\right]}$